Norfishah Ab Wahab
Universiti Teknologi MARA

Published : 7 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 7 Documents
Search

Inter-connected coupled lines Resonator topology for bandpass filter application Mohd Nasiruddin Hushim; Norfishah Ab Wahab; Tn. Syarifah Atifah Tn. Mat Zin; Norlia Ghazali
International Journal of Electrical and Computer Engineering (IJECE) Vol 10, No 3: June 2020
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (927.039 KB) | DOI: 10.11591/ijece.v10i3.pp2523-2534

Abstract

This paper presents an inter-connected side-shorted coupled-line resonator topology as a base cell. The base cell is built from two single-shorted quarter-wavelength coupled-line sections, connected in series to give a half-wavelength coupled-line that creates a single resonance of bandpass filter response. Higher-order bandpass filter is produced by adding new single-shorted coupled-line sections, cascaded in an inter-connected manner to the base cell. This new topology creates a unique arrangement that caused cross coupling effects between the resonators, resulting to the occurrence of transmission zeros that lead to the improvement of selectivity of the higher order bandpass filter response. For validation of concept, 2nd and 3rd order bandpass filters were fabricated using microstrip technology on Roger 3210 substrate with parameter of Ɛr = 10.2, h = 1.27 mm and tan δ = 3x10-3. The filters were measured and the results show good agreement with simulation results.
SIW Circular Cavity Single Mode Filter With Triangle Probe Siti Aminah Nordin; Mohd Khairul Mohd Salleh; Zuhani Ismail Khan; Norfishah Ab Wahab; Latifah Noh; Zakiah Mohd Yusoff
Indonesian Journal of Electrical Engineering and Computer Science Vol 11, No 2: August 2018
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v11.i2.pp672-676

Abstract

A novel substrate integrated waveguide (SIW) circular cavity using triangle probe are proposed in this paper. Prior to this research work, circular cavity resonator was used to achieve a miniaturization for the overall circuit size. The proposed filter provides single resonant mode, TE110. The resonant frequency of TE110 can be adjusted by varying the length and width of the SIW cavity. The proposed filter are designed to operate at frequency 3.75 GHz and implemented on Rogers 3210 substrate with thickness of 0.64 mm. The insertion loss in operating band is less than 0.6 dB and the return loss is better than 24 dB. Simulated result obtained using Ansoft HFSS software.
Pseudo-elliptic narrow bandpass filter using shorted coupled-line of higher order design Mohd Nasiruddin Hushim; Norfishah Ab Wahab; Muhammad Farid Abdul Khalid; Tn. Syarifah Atifah Tn. Mat Zin
Indonesian Journal of Electrical Engineering and Computer Science Vol 14, No 1: April 2019
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v14.i1.pp388-395

Abstract

This paper presents an implementation of quarter wavelength single-shorted coupled-lines for narrow bandpass filter application. It is shown as a new way of creating a single resonance bandpass filter by inter-connected of two single-shorted quarter wavelength coupled-line sections. By adding more single-shorted coupled-line into the configuration, the form of halfwavelength resonator can increase the degree of order of the filter. For the design of 4th order resonator, the coupledlines are arranged inter-connected to each other forming five-fingers lines layout. Due to the interconnection of the coupledlines, transmission zeros appear at the two stopbands which improves the selectivity of the filter response. Investigation on the parametric of the 4th order resonator is conducted to observe the controlling parameters and it’s realiability responses of the resonator. For compactness, five-fingers meandered lines is proposed. It is found that the size of the meandered lines resonator was successfully reduced by 33% compared to the five-fingers straight lines resonator of the same order. For validation of concept, the 4th order meandered lines resonator was designed at 1 GHz and fabricated on RO3210 microstrip substrate with characteristics given as h = 1.27 mm, Ɛr = 10.2 and tan δ = 3x10-3. The measurement results show good agreement with the simulation results.
Prediction of solar irradiance using grey wolf Optimizer-Least-Square support vector machine Zuhaila Mat Yasin; Nur Ashida Salim; Nur Fadilah Ab Aziz; Hasmaini Mohamad; Norfishah Ab Wahab
Indonesian Journal of Electrical Engineering and Computer Science Vol 17, No 1: January 2020
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v17.i1.pp10-17

Abstract

Prediction of solar irradiance is important for minimizing energy costs and providing high power quality in a photovoltaic (PV) system. This paper proposes a new technique for prediction of hourly-ahead solar irradiance namely Grey Wolf Optimizer- Least-Square Support Vector Machine (GWO-LSSVM). Least Squares Support Vector Machine (LSSVM) has strong ability to learn a complex nonlinear problems. In GWO-LSSVM, the parameters of LSSVM are optimized using Grey Wolf Optimizer (GWO). GWO algorithm is derived based on the hierarchy of leadership and the grey wolf hunting mechanism in nature. The main step of the grey wolf hunting mechanism are hunting, searching, encircling, and attacking the prey. The model has four input vectors: time, relative humidity, wind speed and ambient temperature. Mean Absolute Performance Error (MAPE) is used to measure the prediction performance. Comparative study also carried out using LSSVM and Particle Swarm Optimizer-Least Square Support Vector Machine (PSO-LSSVM). The results showed that GWO-LSSVM predicts more accurate than other techniques. 
Performance of Environmental and Energy Audit for Manufacturing Industrial Buildings. Norfishah Ab Wahab; N. A. Sahril; A. Amiruddin; Zuhaila Mat Yasin; N. A. Salim; N. A. Rahmat; N. F. A. Aziz
Indonesian Journal of Electrical Engineering and Computer Science Vol 12, No 2: November 2018
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v12.i2.pp534-541

Abstract

Environmental and energy audit of industrial building is important as it may help in providing a comfortable workplace for the staff as well as to observe the company’s environmental practices during operational hours while managing the energy usage in an efficient manner. It is also important in ensuring the company comply with applicable laws and regulations This paper discusses on the environmental and energy audit to identify the performance of environmental and energy efficiency in two manufacturing industrial buildings with heavy machineries. Analyses on the energy performance, visual comfort and thermal improvement including recommended solutions for optimization of energy efficiency and environmental aspects of the two buildings are presented. Energy efficiency and environmental aspects covered in this audit study are the illuminance of the building, indoor building temperature, relative humidity and carbon dioxide (CO2) percentage in indoor air quality. Jabatan Kerja Raya (JKR) standards is used as a benchmark to observe the illuminance of the buildings, Malaysian Standard 1525 (MS1525) is used as a quality control for temperature and relative humidity, while Department of Occupational Safety and Health, 2005 (DOSH 2005) is used as a quality control for CO2 percentage in air. Based on the results from the audit, the performance for both industrial building is compared. It was found that the energy efficiency and environmental performance for Factory A is better than Factory B.
A review on link adaptation techniques for energy efficiency and QoS in IEEE802.11 WLAN Aliya Syahira Mohd Anuar; Wan Norsyafizan W Muhamad; Darmawaty Mohd Ali; Suzi Seroja Sarnin; Norfishah Ab Wahab
Indonesian Journal of Electrical Engineering and Computer Science Vol 17, No 1: January 2020
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v17.i1.pp331-339

Abstract

Link adaptation is a technique that able to adapt modulation and coding scheme (MCS) based on radio channel conditions. With the exponential increase on the wireless devices nowadays, it contributes to high energy consumption and an increase in carbon dioxide (CO2) emission which contribute to the environmental issue. Researchers have developed proposals to tackle these issues by design algorithms based on link adaptation technique. Nowadays, various link adaptation techniques have been proposed by researchers with target for either Quality of Service (QoS) enhancement as well as energy efficiency. This paper presents A Review on Link Adaptation Techniques for Energy Efficiency and QoS in IEEE802.11 WLAN. In this study, a comprehensive review of the relevant literature published that focus on link adaptation technique in IEEE 802.11 WLAN in improving the energy efficiency and maximize the QoS performance is presented. Link adaptation can be categorized into transmission power control adaptation, transmission data rate adaptation and joint rate adaptation. These adaptations are carried out according to the channel state information (CSI). CSI can be categorized into signal-to-noise ratio (SNR), bit error rate (BER), delay, and queue length.
Liquefied petroleum gas monitoring and leakage detection system using nodemcu ESP8266 and wi-fi technology Suzi Seroja Binti Sarnin; Divine Senanu Ametefe; Nani Fadzlina Naim; Wan Norsyafizan Wan Mohamad; Norlela Ishak; Norfishah Ab Wahab; Norsuzila Ya’acob
Indonesian Journal of Electrical Engineering and Computer Science Vol 17, No 1: January 2020
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v17.i1.pp166-174

Abstract

Liquefied Petroleum Gas which is popularly known as LPG is a clean source of energy which is highly flammable and usually compressed into storage tanks. Due to the flammable nature of LPG it can easily lead to uncontrollable explosions in the presence of any ignition action or may lead to complete depletion of oxygen in a particular area. This study is focused on the fabrication of a system that would detect, monitor and control LPG gas leakages for domestic gas cylinders. A MQ-2 gas sensor was used for the detection of LPG gas leakages, the monitoring aspect was satisfied locally through notifications triggered by LEDs, piezo buzzer and remotely through the use of an application known as Blynk. The control aspect was implemented with the use of a stepper motor which turns off gas cylinder regulators whenever gas concentrations are high. All operations are primary hinged on the NodeMCU ESP8266 controller and Wi-Fi communication technology.